Process and apparatus for drying



Dec. 30. 1924. 1,521,223

R. H. WYLD PROCESS AND APPARATUS FOR DRYING briginai Filed Jan. 21, 1919 Patented Dec. 30, 1924.

LSZLZZB ROBERT H. WYLD, OF GARDEN CITY, NEW YORK.

PROCESS AND APPARATUS FOR DRYING.

Application filed January 21, 1919, Serial No. 272,238. Renewed March 27, 1922. Serial No. 547,272.

To all whom it may concern Be it knownthat I, ROBERT H, WYLn, of Garden City, in the county of Nassau and in the State of New York, have invented a certain new and useful Improvement in Processes and Apparatus for Drying, and do hereby declare that the following is a full, clear, and exact description thereof.

My invention relates particularly to a tively drying materials of various kinds.

The object of my invention is to provide a process and apparatus by means of which materials pf various kinds may be dried in an effective and expeditious manner and in which the heat is transferred from the heating medium with great eiiiciency.

More particularly, the object of my invention is to provide a drying drum having a heating medium used in connection therewith which is applied in such a manner that there is a rapid and effective heat transference from the heating medium to the drum.

Another object is to provide means of this 35 character which is specially adapted for use in drying paper or cloth or any other material in the form of a Web and by the use of which the size of the apparatus may be decreased and the speed of operation thereof 30 increased. v

1 Still another object is to secure an effective heat transference from the heating medium to the heating apparatus by the continual removal of the cooled or condensed heating medium from the surface of the apparatus.

Another object is to provide an effective I means for carrying off any water of condensation which collects in the apparatus.

F urther'objects of my invention will appear from the detailed description thereof contained hereinafter. I

\Vhile my invention is capable of being carried out in many different ways, for the purpose of illustration I shall describe only one way of carrying out the same hereinafter and have shown only one type of apparatus .in the accompanying drawings, in which v c Figure 1 is a lengitudinal section of one rotary drum of an apparatus made in accordance with my invention;

Figure 2 is an end view of anumber of process and apparatus designed for efl'ec-' drums and comprises a transverse section of one of the same, and

Fig. 3 is a vertical section through a portion of one of the drums; and

Fig. 4 is a front elevation of one of said drums.

In the drawings I have shown a plurality of drying drums 1, 2, 3, 4 and 4? made of iron or steel and adapted to receive on the surface of the same a web of paper 5 to be dried. These druins may be supported in any suitable bearings .not shown. The drums are shown as supplied with a heating medium of any desired character, which may, for example, be steam, heated air, etc., by means such as a supply pipe 6 and pipe sections 7, 8, 9 and 9 to convey the steam first into the drum 1 and thence into the drums 2, 3, 4.- and 4 in succession, the steam being supplied from the pipe 6 at the rate of, for

example, 1,000 pounds by Weight per hour,

and the drums beingpreferably of such a size and character that they will each con dense approximately 250 pounds of steam per hour. In order to obtain the same mass flow of steam in the. drum 2 as in the drum 1,

I may supply directly to said drum 2. by

means such. as a pipe 10, an additional 250 pounds of steam by weight per hour, to bring up the total to 1,000 pounds, the same quantity which is supplied to the drum 1. By the condensation of the steam in the drums 3, 4 and 4*, said drums are preferably arranged to utilize the entire quantity of steam fed into the same, the amount received by said drums being, respectively, 750 pounds, 500 pounds and 250 pounds of steam per hour. The additional steamintroduced into the drum 2 by means of the pipe 10 may be supplied by means such as an injector action obtained by locating the outlet end 11 of the pipe 7 in a chamber 12 into which the pipe 10 discharges, so that the steam fed by the pipe 10 at a lower velocity will be effectively'carried into the drum 2 by means such as the high-speed steam issuing from the dlscharge end 11. The steam from the chamber 12 passes into the' drum 2 by means of a pipe 13. a

Referring now particularly to the drum 1, the steam entering the same from the pipe 6 passes, in the embodiment shown,

ltlt) through one of the trunnions of the drum by means such as a pipe 14 and thence into a discharging head 15, preferably having connected thereto a number of radiallydirected pipes 16, which communicate with longitudinally-directed pipes 17, provided with perforations 17 to direct the steam into contact with the inner surface of the drum 1. It will be understood that the pipes 16 and 17 are maintained stationary. The three upper horizontal pipes 17, are shown as each provided with a "cylindrically curved guard plate 18, extending in advance of the same, so as to feed the steam adjacent and conform or confine it against the inner surface of the drum and to discharge the same at a point inside the drum adjacent to the end of an outwardly-directed lip 19 attached to each of said pipes 16. The effect of this is not only to maintain an intimate contact with the steam throughout the inner periphery of the drum,

but to provide a means whereby the condensed water or other liquid upon the inner face of the drum 1 may be continually removed tangentially so as to thereby permit intimate contact between the heating medium and the inner surface of saiddrum. The lip 19 serves the purpose of assisting in the tangential removal of the film of liquid from the interior of the drum 1, inasmuch as it will provide a barrier of swiftly-moving escaping steam immediately adjacent to the inner periphery of said rum and beneath the current of steam which is issuing at the end of the guard 18. By this means the liquid, as for example condensed steam, is continually thrown toward the center of the drum, whence it is collected in means such as pan 20 supported byv the remaining pipe 17, as well as by links 21 and 22 extending downwardly to said pan from an axially-positioned condensate pipe 23, having a depending branch pipe 24;, located above the pan 20, so that the condensate passes out of the drum through vthe remaining trunnion and is connected by discharge pipe 25 to a vacuum pump 26 of a any desired character. Said pan preferably has at its forward end a downward extension 27, terminating adjacent to the inner surface of the drum in a manner similar to the location of the lips 19, and the other end 28.0f said pan 20 is preferably positioned in a manner similar to the location of the forward end of one of the guard plates 18. The pipe'17, which is connected to the pipe-16, which supports the pan 20, is preferably constructed in the same manner as the other pipes 17, with the necessary perforations to provide a current of the heating medium. Around the portion of the drum 1 which is utilizedfor heating the web of paper 5, there is shown an exterheated air by means of a fan 32 located therein and driven by a belt 33 passing over means such as a pulled 34 on the fan 32 and a pulley 35 attached to one of the trunnions of'the drum 1. Leading to the fan 32 there is preferably a hot air supply pipe 36. The steam which is not condensed with in the drum 1 passes out by a pipe 36,

which is connected to the pipe 7, Fig. 1.

The constructionof the drums 3 and 4 may be the same as the construction of the drum 1.

The drum 2 is preferably constructed in the same manner as'the drums 1, 3 and 4, except in the following respects. instance, the upper surface of the. drum is the portion which is utilized for heating the web of paper, and it is this surface, therefore, which is supplied with an exterior guard plate 29. Upon the interior of this drum 2 there need be no lower vertical pipe 16 and attached pipe 17, as it is not necessary in this instance to heat the lower portion of the drum. In the case of this drum 2, furthermore, the steam inlet pipe is preferably the pipe 13 and the uncondensed steam passes out by means such as the pipe 8.

The construction of the drum 4 may be exactly the same as in the case of the drum 2, except that there need be no inlet pipe 10 and injector chamber 12 for the introduction of additional steam.

In the operation of the described embodiment of my invention, steam which may be introduced at the rate of 1,000 pounds per hour, and which may be supplied at any pressure, but which is preferably exhauststeam having a pressure of from 5 to 10 pounds per square inch and a temperature In this i of 220 F., is supplied by the pipe 6 to the drum 1, which is being continually rotated and receives continually thereon a traveling web of moist paper to be dried, as for example in the manufacture of paper immediately after the web has been formed.-

is condensed in this manner is caught by the pan 20 and discharged through the agency of the pipes 24 and 25 and the vacuum pump 26. In this way there may be 250 pounds by weight of the steam condensed per hour, and there is thus left a remainder of 750 pounds of steam per hour, which is fed through the drum 1 at a high speed, and which, consequently, provides a mass flow of great volume and velocity to thus provide an effective heat transference between the heating medium and the body of the drum 1; As a result, there is obtained a very efiicient and rapid transference of the heat from the heating medium to the drum and, as a consequence, from the drum to the web of paper 5. This result is assisted by the accelerated evaporation obtained through the agency of the currents of heated air applied to the exterior of the drum.

The remaining drums 2 3, 4 and 4 Operate in a similar manner, except that in the drum 2 there may be an additional 250 pounds of steam introduced per hour, so as to build up the mass flow of steam therein to 1,000 pounds of steam per hour,the amountsupplied to the drum 1; and in the drums 3, 4 and 4 there are decreasing quantities of steamsupplied,that is to say, 750, 500 and 250 pounds of steam per hour, respectively, owing to the condensation of 250 pounds of steam per hour occurring in each of these drums. Furthermore, in the drums 2 and 4 there is no special heating means provided for the lower portion of the same inasmuch as the Web 5 only passes above the upper portions thereof.

Again it will be understood that no special heating means is necessary in the upper portions of drums 1, 3 and 4 as the upper portions thereof do not heat the traveling Web.

While I have described my invention above in detail, I wish it to be understood that many changes may be made therein Without departing from the spirit of the same.

I claim:

1. The process which comprises, drying a material by supporting the same upon a heating apparatus and supplying to the latter a heating fluid in larger quantity per unit of time than is able to transfer all of its heat to said apparatus in that period and then applying to said material thereafter part of the efiluent quantity of the heating medium after adding to said heating medium an additional quantity of said medium to offset loss thereof when applied asbefor mentioned to the material to be dried.

2. The process which comprises drying a material by supporting the same upon a heating apparatus and supplying to the latter a heating fluid in larger quantity per unit of time than is able to transfer all of its latent heat to said apparatus in that period and then applying to said material thereafter part of the efiluent quantity of the heating medium after adding to said heating medium an additional quantity of said medium to olfset loss thereof when applied as before mentioned to the material to be dried.

3. A drying apparatus comprising a drum and means for distributing a heating medium in the interior thereof comprising a guard plate extending along the inner periphery of the drum and a lip located very near the inner surface of the drum adjacent to the forward end of said guard plate.

4. A drying apparatus comprising a drum and means for distributing a heating medium in the interior thereof comprising a guard plate extending along the inner periphery of the drum, a lip located very near the inner surface of the drum adjacent to the forward end of said guard plate and a radially-directed supply pipe adapted to supply the heating medium beneath the guard plate.

5. A drying apparatus comprising a drum and means for distributing a heating medium in the interior thereof comprising a guard plate extending along the inner periphery of the drum and a lip located very near the inner surface of the drum adjacent to the forward end of said guard plate, said guard plate serving as a pan to collect any condensate.

6. A drying apparatus comprising a drum and means for distributing a heating medium in the interior thereof comprising a guard plate extending along the inner periphery of thedrum, a lip located very near the inner surface of thedrum adjacent to the forward end'of said guard plate, and a radially-directed supply pipe adapted to supply the heating medium beneath the guard plate, said guard plate serving as a pan to collect any condensate.

7. A drying apparatus comprising a drum and means for distributing a heating medium in the interior thereof comprising a guard plate extending along the inner periphery of the drum, a lip located verynear the inner surface of the drum adjacent to the forward end of said guard plate,-

said guard plate serving as a pan to collect 1 drum and means supply the heating medium beneath the guard plate, said guard plate Serving as a pan to collect any condensate, and means for removing the condensate from said-pan.

9. A drier comprising a rotatable drum mounted on an axle, a steam pipe passing through the axle and connected to a discharge head, perforated pipes connected to the. latter and arranged so that steam will pass through the perforations close to the interior surface of the drum guard plates and lips near and against said surfaces respectively to scrub off the water and direct the steam and water tangentially and then to the interior of the drum whence the water is removed.

10. A drier comprising a series of rotatable drums mounted on axles, one of said drums having a steam pipe passing through the axle connected to a discharge head, perforated pipes connected to the latter and arranged so that steam will pass through the perforations close to the interior surface of the drum, guard plates and lips near and against said surfaces respectively to scrub off the water and direct the steam and water tangentially and then to the interior of the drum whence the water is re moved, and a steam discharge pipe leading from the interior of the drum through the axle to the next drum of said series.

11. A drying a paratus comprising a or distributing a heat ing medium in the interior thereof comprising a guard plate extending along theinner periphery of the drum, a lip located near the inner surface of the drum adjacent the forward end of saidguard plate,

a pipe leading from the'linterior of thedrum through the hollow axle and connecting 'to the steam inlet of a second drum whereby steam is admitted to the second drumfrom the first drum, and a second drum so connected.

.mission pipe leading to the third drumcof the trio.

13. A drier comprising a rotatable drum,

mounted on an axle, a steam pipe passing through the axh? and connected to a discharge head, perforated pipes connected to the latter and positioned close to the interior surface of the drum,'and guard plates adjacent said perforated pipes for the purpose of causing steam to pass rapidly along the interior surface of the drum.

14. A drying apparatus comprising a drum and means for distributing a heating medium in the interiorthereof comprising a guard plate extending along the inner periphery of the drum.

15. A drying apparatus comprising a drum mounted for rotation on an axis, means for admitting steam or other heating medium through the axis, a steam delivery pipe near, the interior surface of the drum and a guard plate associated with said dehvery' ipe so as to cause the steam to pass along t e interior surface of the drum.

16. A drying apparatus comprising a rotatable drum mounted upon an axis, a steam pipe through the axis, and a steam delivery pipe near the interior surface of the drum, a guard plate adjacent the delivery pipe so as to cause the steam issuing from "said pipe to pass rapidly along the interior surface of the drum, and means for removing the condensed water therefrom.

17. A drying apparatus comprising a drum mounted for rotation on an axis, a steam delivery pipe through the axis, a perforated steam delivery pipe nears the interior surface of the drum and an annular partition within the drum separating the delivery pipe from the interior thereof so that steam emerging from the perforations will be confined to the annular space and force condensed water from the interior surfaceof the drum.

18. A drying apparatus comprising a drum and means for distributing a-heating medium tange tially to the inner surface thereof, and means for keeping said medium from leaving said surface immediately thereafter.

19. A drying apparatus comprising a drum, means for distributing a heating medium tangentially to the inner surface thereof, means for keeping said medium in contact with said surface for a part of its arc, and means'for removing air and water from the interior of the drum.

20. In a process for drying a web of mate rial by passing it over an internally heated drum, the improvement characterized by injecting the heating medium tangentially against the inner surface of the drum so as to keep away condensed water.

21. In a process for drying a web of material by passing it over' an internally heated. drum, the improvement characterized by v directing the heating medium tangentially against the inner surface of the drum and keeping it in contact therewith along a portion of the surface of the drum.

22. In a process for drying a web of material by passing it over an internally heated drum, the improvement characterized 'by directing the heating'medium tangentially against the inner surface of the drum, keeping it in contact therewith along a protion of the surface of the drum and removing condensed water and air from the interior of the drum.

23. A process of drying a web of paper by passing it over an internally heated drum, wherein steam is directed against the interiorsurface of the drum and water and air are immediately removed from contact with 10 ROBERT H. WYLDQ Witnesses:

ARTHUR WVRIGHT, LILLIAN M. COOKE. 

